The overall goal of this project is to determine the principal factors governing the transfer of information from retinal photoreceptors to bipolar cells. Specific aims include i) to measure both the dynamic gain and the transfer function of the rod-bipolar cell synapse, ii) to analyze the synaptic voltage noise across the bipolar cell membrane and thereby to determine the signal-to-noise ratio of the synapse, iii) to generate an equivalent electrical model of the bipolar cell dendritic arborization, based on serial electron-micrographs of HRP stained bipolar cells and iv) to assess the signal transfer properties of the bipolar cell dendritic arborization so that its role in the spatial integration of rod signals can be properly understood. The techniques to be used include intracellular recording under visual control from isolated, perfused retinal slices and the study of serial thick sections of retinal tissue under the high-voltage electron microscope. The role of the bipolar cell in signal transfer from receptors to bipolar cells is poorly understood at present. This project should open new areas of understanding of retinal function and perhaps contribute to an understanding of certain retinal disorders.